The present invention relates to visual inspection of water-immersed portions of existing nuclear reactor vessels and, more particularly, to an inspection system involving manual manipulation of a television camera through which the reactor components are viewed.
Periodic inspections of nuclear reactor vessels are required for obvious safety reasons in connection with their operation. Among the portions which must be inspected to detect any scratches, cracks, fissures or other possible sources of leaks are components which are at all times completely immersed in water during both operation and inspection. Such components include feed water spargers, core spargers and supply piping therefor, and welded attachments, as well as the internal stainless steel cladding of the reactor vessel.
The most convenient and effective means for performing such inspections is normally to scan the areas under inspection with a television camera which transmits a video signal to a monitor displaying the area for visual determination of its condition. Although a number of systems have been provided for carrying out inspections in this manner, they normally involve quite elaborate and expensive equipment for mounting a camera within the reactor vessel and moving it in the desired manner to scan the areas to be inspected. Furthermore, the inspection system itself involves the installation of equipment which may require periodic adjustment or repair at inconvenient locations within the reactor vessel.
Accordingly, it is a primary object of the present invention to provide a simplified and economical system for visually inspecting water-immersed areas within nuclear reactor vessels.
Another object is to provide a method, and apparatus useful in the implementation thereof, for performing visual inspections, through a television camera and monitor, of internal areas of reactor vessels which is both efficient and effective.
A further object is to provide an inspection system for nuclear reactor vessels which involves no apparatus permanently mounted within the vessel.
Still another object is to provide a novel and improved positioning device, and means for selective manipulation thereof, for a television camera and associated lighting equipment for use in visual inspection of nuclear reactor vessels.